CYBERNETIC MODEL FOR SYNTHESIS OF POLY-BETA-HYDROXYBUTYRIC ACID IN ALCALIGENES-EUTROPHUS

The pathway of poly-beta-hydroxybutyric acid (PHB) exhibits a mode of transcriptional control induced by environmental stress. A new cyberne tic model for coordinated regulation of stress-induced metabolism was developed to predict the growth and the synthesis of PHB in Alcaligene s eutrophus. A plausible objective for this control is optimization of acetyl-CoA utilization so that the cells have a high degree of flexib ility in their catabolism. The state equation for key protein synthesi s was assumed to have a dependence on the nonlinear control variable. The proposed model can demonstrate the mixed-growth-associated synthes is of PHB. Reported unstructured models were compared statistically wi th the result of the simulation derived from the proposed model using the experimental data of this study and the literature. The proposed m odel appeared to provide an excellent description for the overall ferm entation rage. (C) 1994 John Wiley & Sons, Inc.